Die klinische Bedeutung der Konduktanz und Suszeptanz bei 220 und 660 Hz

Summary The tympanometric measurement of conductance and susceptance is useful for getting separated informations about mass, stiffness, and friction of the middle ear structures. From clinical view such a method has to facilitate the preoperative diagnosis in not clarified cases of air borne hearing loss like otosclerosis, stapes-fracture or incus-luxation. In these cases we measured conductance and susceptance by probe-tone-frequencies of 220 and 660 Hz. The preoperative results are compared with the intraoperative diagnosis.     

High-frequency Bekesy audiometry: IV. Normative aspects for normal-hearing young adult

Normal-hearing young adults Ss (10 M, 20 F) produced Bekesy threshold tracings on a modified Grason - Stadler E-800 audiometer for pure tone in 2-kc/s increments from 7-19 kc/s, using as transducer an air-coupled 1/2-inch condenser microphone. Mean threshold functions and variances, the proportion of Ss responding at each frequency, and the role of sex-related differences were analyzed and discussed. Although the same was too small to yield reference equivalent threshold SPLs for high-frequency audiometry using the present apparatus and procedures, the data are useful for a future full-scale normative study.     

Frequency-specific objective audiometry: tone-evoked brainstem responses and steady-state responses to 40 Hz and 90 Hz amplitude modulated stimuli

Tone-evoked Auditory Brainstem Responses (tone-burst ABRs) and Auditory Steady-State Responses (ASSRs) with 40 or 90 Hz amplitude modulation (AM) were compared, using the same equipment and recording parameters, to determine which of these three methods most accurately approached the behavioural hearing thresholds in response to 500 Hz and 2000 Hz stimuli in eleven awake adults with normal hearing. Estimates of the thresholds obtained with the three methods were 10, 18, and 26 dB SL at 500 Hz; and 10, 12, and 22 dB SL at 2000 Hz; using 40 Hz ASSR, 90 Hz ASSR, and tone-burst ABR, respectively. ASSRs with 40 Hz AM stimuli produced significantly better results (lowest thresholds with SD=0), whereas the wave-V analysis on the tone-burst ABR produced the poorest results. In the averaged ABRs, a robust steady-state potential was also visible. Analysis of those steady-state responses showed estimated thresholds of 13 and 14 dB SL (at 500 and 2000 Hz, respectively), thus considerably better than the estimated thresholds from the wave-V analysis. It is concluded that the 40 Hz ASSR showed superior results, especially at 500 Hz.     

Frequency-specific objective audiometry: Tone-evoked brainstem responses and steady-state responses to 40 Hz and 90 Hz amplitude modulated stimuli

Tone-evoked Auditory Brainstem Responses (tone-burst ABRs) and Auditory Steady-State Responses (ASSRs) with 40 or 90 Hz amplitude modulation (AM) were compared, using the same equipment and recording parameters, to determine which of these three methods most accurately approached the behavioural hearing thresholds in response to 500 Hz and 2000 Hz stimuli in eleven awake adults with normal hearing.

Estimates of the thresholds obtained with the three methods were 10, 18, and 26 dB SL at 500 Hz; and 10, 12, and 22 dB SL at 2000 Hz; using 40 Hz ASSR, 90 Hz ASSR, and tone-burst ABR, respectively. ASSRs with 40 Hz AM stimuli produced significantly better results (lowest thresholds with SD?=?0), whereas the wave-V analysis on the tone-burst ABR produced the poorest results. In the averaged ABRs, a robust steady-state potential was also visible. Analysis of those steady-state responses showed estimated thresholds of 13 and 14 dB SL (at 500 and 2000 Hz, respectively), thus considerably better than the estimated thresholds from the wave-V analysis.

It is concluded that the 40 Hz ASSR showed superior results, especially at 500 Hz.

Sumario

Utilizando el mismo equipo y los mismos parámetros de prueba, se compararon las respuestas auditivas de tallo cerebral evocadas por tonos ABR de burst tonales y las respuestas auditivas de estado estable (ASSR) con 40 o 90 Hz de modulación de amplitud (AM), para determinar cual de estos tres métodos se aproximaba con mayor exactitud a los umbrales auditivos comportamentales en 500 y 2000 Hz, en 11 adultos normoyentes despiertos.

La estimación de los umbrales obtenidos con los tres métodos fueron 10, 18 y 26 dBSL a 500 Hz y 10, 12 y 22 dBSL a 2000 Hz con 40 Hz ASSR, 90 Hz ASSR y ABR de pips tonales, respectivamente. Las ASSR con estímulo de 40 Hz AM produjeron resultados significativamente mejores (umbral menor con SD?=?0), mientras que el análisis de la onda V en los ABR con burst tonales generó los resultados más pobres. En los ABR promediados, se pudo observar un potencial de estado estable robusto. El análisis de las respuestas de estado estable mostró umbrales estimados de 13 y 14 dBSL (500 y 2000 Hz, respectivamente), que son considerablemente mejores que los umbrales del análisis de la onda V. Se concluye que las ASSR de 40 Hz muestran resultados superiores, especialmente a 500 Hz.     

Normative disfluency data for early childhood stuttering.

Although the past 50 years of research on early childhood stuttering and normal disfluency have produced vital information on the general features of disfluent speech behavior of young children, an adequate normative reference for early stuttering does not exist. The purpose of this report is to provide such reference and to provide a basis for clinical needs of differential diagnosis of stuttering from normal disfluency. Data are presented from 90 stuttering children ages 2 to 5 within 6 months of stuttering onset and from 54 age-matched normally fluent children. Means for disfluency types are presented. No significant differences were found for gender or for age. Stuttering-like disfluencies (SLD) did differ significantly for the stuttering and fluent groups, but other disfluencies (OD) did not. A weighted SLD is defined to further clarify differences between the groups. The pattern of disfluency types for normally fluent and for mild, moderate, and severe stuttering is presented. Stuttering is shown to be qualitatively as well as quantitatively different from normal disfluency even at the earliest stages of stuttering. Clinical and research implications are discussed.     

Psychoacoustical tuning curves. Normative data for clinical use.

This normative study presents a clinically applicable method with which to obtain Psychoacoustical Tuning Curves: data are obtained with clinical audiometers, and measurements are performed on normal-hearing non-trained volunteers. A simultaneous masking method with test frequency of 4,000 Hz was used, withmasking being incremented in 5 dB or 1 dB steps. One group of subjects was tested three times with 5 dB incrementing steps to evaluate the method's reproducibility. A second group of subjects was measured twice with 1 dB incrementing steps, to compare the reproducibility of the 1-dB step measurements, and the difference between the 1-dB step and 5-dB step measurements. All the data were evaluated as normative values. The method presented proves to have a good reproducibility. Although testing with 1-dB incrementing steps provides more accurate measurements and curves with steeper slopes, the 5-dB incrementing step method is more practicable. Interest variability evaluation indicates that differences between two measurements performed on the same person exceeding 120 Hz (2 SD) bandwidth can be interpreted as significant.     

80 Hz auditory steady-state responses (ASSR) at 250 Hz and 12,000 Hz

Although measurement of the detection limits of the 80 Hz auditory steady-state response (ASSR) has proven to be a reasonably reliable tool in estimating hearing sensitivity in the mid-conventional audiometric frequencies (e.g. 1000 and 2000 Hz), results in the literature suggest potentially diminishing performance at 500 Hz and above 4000 Hz. The primary goal of this work was to examine the accuracy of threshold estimation via ASSR measurement for carriers more toward the audiometric extremes. At the same time, different stimulus and recording protocols than those commonly employed in ASSR testing were examined. Using a two-channel recording system, ASSRs were obtained from 15 normal-hearing young adults for an amplitude-modulated carrier of 250 Hz and repeated tone bursts of 10,000-16,000 Hz, gated using a Blackman window. Results attest to the ability to record ASSRs to a wide range of carrier frequencies but also suggest that accuracy of threshold estimation suffers toward the audiometric extremes. Feasibility of ASSR-based high-frequency audiometry is demonstrated in principle, but it is not clear that this method will permit adequate sensitivity and accuracy to support such applications as ototoxicity monitoring.     

36个月内婴幼儿1000Hz和226Hz探测音声导抗的特点和意义

目的分析0-36个月婴幼儿226 Hz和1000 Hz探测音声导抗结果,探讨在临床上如何选择226 Hz和/或1000 Hz探测音声导抗方法将1645例(共3290耳)0-36个月婴幼儿按听力评估结果分为两个大组:听力正常组938例(1876耳)和听力异常组707例(1414耳),按月龄分为七个小组:第一组:新生儿(≦28天)54例(108耳),其中听力正常组34例(68耳);第二组:2³月龄355例(710耳),其中听力正常组149例(298耳);第三组:43月龄355例(710耳),其中听力正常组149例(298耳);第三组:4⁶月龄537例(1074耳),其中听力正常组201例(402耳);第四组:76月龄537例(1074耳),其中听力正常组201例(402耳);第四组:7⁹月龄236例(472耳),其中听力正常组143例(286耳);第五组:109月龄236例(472耳),其中听力正常组143例(286耳);第五组:10¹2月龄97例(194耳),其中听力正常组62例(124耳);第六组:1312月龄97例(194耳),其中听力正常组62例(124耳);第六组:13²4月龄259例(518耳),其中听力正常组249例(498耳);第七组:2524月龄259例(518耳),其中听力正常组249例(498耳);第七组:25³6月龄107例(214耳),其中听力正常组100例(200耳)。结果正常组226 Hz和1000 Hz探测音鼓室声导抗图均存在正峰,并且均以宽大的单峰型最多见,少数为双峰型.其中226 Hz单峰1403耳(74.79%),双峰290耳(15.46%);1000 Hz单峰1407耳(64.07%),双峰175耳(5.17%).第一至第五月龄组组间1000Hz与226Hz探测音声导抗正常和异常结果均有统计学意义(P<0.05)。其中第一至第四月龄组1000Hz组一致率(97.06%,91.95%,91.04%,81.82%)均高于226Hz组(38.24%,68.46%,66.92%,66.78%),第五月龄组226Hz组的一致率(95.16%)高于1000Hz组(58.87%)。第六至第七月龄组组间1000Hz与226Hz探测音声导抗正常和异常结果均有统计学意义(P<0.05)。结论单纯226 Hz探测音鼓室声导抗测试不能准确反映O36月龄107例(214耳),其中听力正常组100例(200耳)。结果正常组226 Hz和1000 Hz探测音鼓室声导抗图均存在正峰,并且均以宽大的单峰型最多见,少数为双峰型.其中226 Hz单峰1403耳(74.79%),双峰290耳(15.46%);1000 Hz单峰1407耳(64.07%),双峰175耳(5.17%).第一至第五月龄组组间1000Hz与226Hz探测音声导抗正常和异常结果均有统计学意义(P<0.05)。其中第一至第四月龄组1000Hz组一致率(97.06%,91.95%,91.04%,81.82%)均高于226Hz组(38.24%,68.46%,66.92%,66.78%),第五月龄组226Hz组的一致率(95.16%)高于1000Hz组(58.87%)。第六至第七月龄组组间1000Hz与226Hz探测音声导抗正常和异常结果均有统计学意义(P<0.05)。结论单纯226 Hz探测音鼓室声导抗测试不能准确反映O¹0月龄婴幼儿的中耳功能,1000 Hz探测音声导抗测试能更好的评估O10月龄婴幼儿的中耳功能,1000 Hz探测音声导抗测试能更好的评估O¹0月龄婴幼儿的中耳功能;;226 Hz探测音鼓室声导抗测试能客观反映1110月龄婴幼儿的中耳功能;;226 Hz探测音鼓室声导抗测试能客观反映11³6月龄婴幼儿的中耳功能。     

Hypersensitivity to sound--questionnaire data, audiometry and classification

This study included consecutive case histories and audiometry of 100 patients with hypersensitivity to sounds. There are several different conditions with the symptom of hypersensitivity to sounds. Hyperacusis is one of those and is seldom described in the literature. The term hyperacusis is often used synonymously with hypersensitivity to sound. We propose that there is a specific condition that could be termed hyperacusis. Hyperacusis is often elicited by loud sounds or by a number of other traumata or diseases. It is not typical of occupational noise exposure (with the exception of exposure to music). The typical patient is relatively young, the mean age being approximately 10 years less than for a population of patients with tinnitus or noise-induced hearing loss. In addition to hypersensitivity to sound, the patients often suffer from tinnitus (86%). Sounds are frequently painful and exposure to loud sounds worsens the condition for some time. The patients often have headaches. Pure tone audiograms show normal hearing or a slight high tone loss. The uncomfortable loudness level is markedly decreased, mostly less than 90 dB HL. Patients with hyperacusis may also be divided into those hypersensitive to the loudness of sounds with a decreased pure tone uncomfortable loudness level and those hypersensitive to certain specific sounds irrespective of loudness showing relatively high pure tone uncomfortable loudness levels and decreased uncomfortable loudness levels to specific sounds. With a careful history other conditions with the symptom of hypersensitivity to sound can be excluded.     

Reproducibility of hearing threshold measurements. Supplementary data on bone-conduction and speech audiometry

The reproducibility of bone-conduction pure-tone audiometry and speech recognition thresholds has been tested in groups of normal-hearing subjects. Each person was tested twice during the same day, and the test-retest difference was calculated. The reproducibility is presented as the standard deviation of this difference. Bone-conduction threshold measurements have a high degree of test-retest precision, whereas air-bone gaps show a large range of distribution in these normal-hearing subjects. This makes the interpretation of such gaps spurious when values are below 20-30 dB. Speech recognition threshold has the highest degree of test-retest precision of all audiometric tests, and this is probably due to the steep slope of the psychometric function at 50% intelligibility. A more detailed graphic presentation of the 50% point of intersection will bring the reproducibility down to less than 2.5 dB.     

A comparison of pure-tone thresholds as measured by delayed feedback audiometry, electrodermal response audiometry, and voluntary response audiometry.

One hundred unselected patients seen for medical-legal evaluation were tested for pure-tone thresholds by delayed feedback audiometry (DFA), electrodermal response audiometry (EDRA), and voluntary response audiometry (VRA). The EDRA method was successful in 73% of the patients while the DFA method was successful in 88% of the patients. Eighty-six percent of the DFA thresholds obtained were within 10 dB of the patients' VRA thresholds. When both DFA and EDRA were successful, 88% of the DFA thresholds were within 10 dB of the EDRA thresholds. Ninety-six percent of the EDRA thresholds obtained were within 10 dB of the patients' VRA thresholds. Although DFA is not as precise in predicting threshold as is EDRA, it is successful in a significantly greater number of patients than is EDRA and is a useful clinical tool in medical-legal evaluation for hearing loss.     

High-frequency audiometry. Age and sex variations

286 normal subject representing both sexes and seven age groups from 10 to greater than or equal to 70 years were tested with both conventional pure tone audiometry and high frequency audiometry (4--20 kHz) using a previously described free field system. The subjects were selected according to very strict criteria. Results from conventional audiometry are similar to other findings in presbycusis studies, though sex difference was seen for the oldest age groups, but only at the frequencies 4 and 5 kHz where the male population showed a significantly poorer hearing. The same sex difference was observed by high frequency audiometry at 4 and 8 kHz. From 10--20 kHz no sex difference was present. At the high frequencies there is an abrupt decrease in hearing sensitivity already from youth. Hitherto, no international standard for zero dB hearing level exists for frequencies above 8 kHz. It is questioned whether a general standard is meaningful at all and that normative data for various age groups should instead be used as a reference level.     

Computerized measurement of speech intelligibility. II. Normative data from a 'closed response' test.

A Danish Four Alternative Forced Choice (4AFC) test was presented to normal-hearing and cochlearly hearing-impaired listeners in two background noises: a modulated, speech-spectrum-shaped noise and an 8-persons babble noise. At the presentation to the hearing-impaired subjects the test signals were given a frequency-dependent amplification in accordance with the POGO-fitting method. Normative data are presented which indicate that 4AFC is a valid test in spite of lack of homogeneity between the alternatives allowed. On the other hand, a learning effect is demonstrated which affects the reliability. A computer-assisted analysis of the obtained consonant confusions reveals a predominance of confusions among initial consonants having the same voicing.     

正弦谐波加速试验的正常参考值及初步临床应用

目的 测量正弦谐波加速试验的正常参考值和常见疾病的参数值,探讨各检测参数值的临床意义.方法 正常人120例.梅尼埃病患者21例,双側外周前庭病变2例,急性单侧前庭功能受损15例,中枢病变10例,全部完成正弦谐波加速试验.结果 年龄大者的定标平均时间长.相位值随频率升高而降低,增益随频率升高而变大,低频相位值重复性好.梅尼埃病患者中7例在间歇期都正常,14例发作末期的患者均有异常,11例相位异常,3例增益异常,10例有不对称,8例患者合并2项指标的异常,不对称的患者均有自发性眼震.单侧急性前庭功能受损患者出现相位异常的11例;增益降低10例,见于0.08 Hz以上频段;不对称的有6例,其中5例有自发性眼震.双侧前庭功能受损的患者增益显著降低.中枢损伤10例中相位异常7例,低增益2例,不对称有4例,不对称者均无自发性眼震.结论 正弦谐波加速试验的正常参考值在一个比较窄的范围内,相位是其最重要的指标.     

Evoked cerebral potential audiometry and hearing threshold.

Audiometric testing by means of the nonspecific evoked cerebral potential (NECP) was performed in 20 children (11 with normal hearing, 6 with conductive and 3 with sensorineural hearing loss). The threshold as determined by this method was 20-30 dB higher than the threshold of the subjective tonal audiograms in the majority of the cases. Only in two cases the difference was up to 70 dB. There were no significant differences between the results of the methods in the three groups of children. The possible reasons for the described discrepancy between the thresholds of the ECP audiometry and the subjective tonal audiometry are discussed. It is pointed out that either of the two methods explores one of two different functional systems: the nonspecific activating system of the brain stem and the auditory pathway. It is suggested that the observed discrepancy between the results of the two methods may mainly be due to different thresholds of the two systems. To avoid false negative results of the ECP audiometry in subjects with 'constitutionally' low amplitude of the NECP it is proposed to routinely determine the amplitude of the NECP produced by somatosensory stimuli. Careful evaluation of the recorded data can improve the diagnostic value of ECP audiometry.     

High-frequency audiometry. Masking of air- and bone-conduction signals.

Interaural attenuation has been investigated for both air-conduction and bone-conduction signals in the frequency ranges 0.25-18 and 0.25-16 kHz respectively. Ear canal occlusion is recommended when using the Koss HV/1A earphone for BC masking, as acoustic transmission occurs through the headset in the high-frequency range. Minimum masking levels for 1/3-octave filtered white noise were established for bone-conduction signals in the frequency range 8-16 kHz. Central masking of bone-conduction signals proved to be of the same order of magnitude in the conventional- and high-frequency ranges, while the cross-masking level was approximately 10-15 dB lower above 6 kHz. Recommendations are made for a masking procedure in the high frequency range.